Means for reproduction of sound films



R. KOLLER Sept. 29, 1931.

' BARS FOR REPRODUCTION OF SOUND FILMS Filed May 22, 1950 2 Sheets-Sheet l2 Patented Sept. 29, 1931 UNITED STATES PATENT OFFICE ROBERT ROLLER, F BADEN, SWITZERLAND MEANSIFOR REPRODUCTION OF SOUND FILMS Application filed May 22, 1930, Serial No. 454,803, and in Switzerland February 14, 1929.

` This invention relates to a device for the reproduction of sound films.

It has previously been proposed for the purpose of obtaining exact local synchronizw tion of the sound and the pictorial representationy to arrange behind the projection screen several sources of sound which are preferably uniformly distributed and which, by means of a controlling band, are alternately brought into action individually or in groups in correspondence with the shift ofthe field of action.

The invention has for its object certain improvements whereby there is obtained greater exactitude of synchronization of the pictorial representation and the sound and which renders it possiblev to arrange the Contact devices influenced by the controlling band at any point independent of the arrangement of the device for unwinding the said band.

eliminate the unavoidable noises which are heard when controlling the sound by means of the controlling band, the contact devices included in the circuits containing the sources of sound.

Yet another object is to provide improved means which render possible simple and convenient production of thecontrolling band with great exactitude.

The primary feature of the invention resides in the circumstance that the controlling band divided into several zones in accordance with several sources of sound so co-operates indirectly or directly with vthe movable members of several contact devices included in the circuits containing the sources of sound that, under the action ofthe apertures, the movement of the contact members necessary to close the circuits is effected. The movement 40. of these contact members ispreferably effected pneumatically, e. g., each zone of the band forming a closure for the delivery end of an air pipe in which is air at super-atmospheric or sub-atmospheric pressure` the contact member or a controlling member connected therewith being movable in said air pipe.

0n unmasking the mouth of the pipe by the apertures in the band, there is effected Vbetween the air pipe and the atmosphere a sudden balance of' pressure so that the con- Further, the invention has for its object to tact member disposed within the pipe or the controlling member connected therewith is set in movement for the purpose of closing the circuit. i

In order to effect the production of the controlling band with simple means without necessity for exercise of special skill, according to the invention there is employed a new method according to which the domains of several sources of sound are differentially 60 reproduced on the projection screen during simultaneous slow unwinding of the film band and of the controlling band while at the same time a number of tools, equal to the number of sources of sound, for producing the apertures in the controlling band in accordance with the shift of the field of action m the several sound domains are alternately brought into action in the relative zones of the controlling band. l 7

In a particularly simple embodiment of this method there is employed for controlling the tools a set of keys arranged similarly to the domains of sound which are rendered visible on the projection screen.

An embodiment ofthe device for representing the film and an embodiment of a device for producing the controlling band are illustrated in the accompanying drawings.

In the drawings Fig. 1 shows in cross-see- 90 tion the complete device for controlling a source of sound. f

, Fig. 2 represents diagrammatically the device used in effecting the representation.

Figs. 3 and 4t shown in end elevation and 85 in front elevation the device for producing the controlling bands.

Referring to the drawing, thecontrolling band B united with the film band F is divided into eight zones B1, B2 .138.

In accordance with thisdivision there are arranged behind the projection screen' A eight sources of sound F1, F2 F8 which by the stencil openings L of the controlling band B are alternately brought into action 95 individually or in groups. The controlling band B is unwound from the roller a andy led under tension over a segment b of a hollow cylinder to a roller o. The hollow cylindrical segment .7) is provided with eight 100 apertures d arranged alongside one another of which each is masked by a zone of the controlling band B and is of about the breadth of a stencil opening L in the controlling band. Each aperture d forms the mouth of a small conduit e leading from the cylinder f. In accordance with the number of apertures d eight conduits e and cylinders f are arranged alongside one another. All the cylinders f are connected by conduits g leading from their lower ends to a common collector pipe h which is connected with an air exhaust means such as an air pump not shown in the drawing. In each cylinder f there is provided a poppet valve z' which is carried by a stem 7' guided :tor movement in the cylinder f. The stem y' is subject to the action of a helical spring le which opposes the closing movement of the valve proper c' and holds it open. At the lower end of the stem j is arranged a contact member Z insulated from the rod and connected by a conductor m to one pole ofthe corresponding electrically actuated source of sound. Arranged opposite all the contact members Z is a bus bar n which is connected by a conductor o with the other poles of all the sources of sound. IVith the illustrated arrangement and construction of the piston of the valve proper z the air pump connected to the collector 7L must be arranged to exercise a sucking action. As soon as an aperture d in the segment is unmasked by a stencil opening L of the controlling band B, then, due to the vacuum in the relative cylinder f and the conduit e, therevis set up an air current whereby the valve proper is moved downwards in opposition to the action of the spring c, until it is arrested by the seat z". Thereby the contact member Z is brought in contact with the bus bar n and the circuitfor the relative source of sound is closed. This circuit is not opened until the aperture d is again screened by the controlling band B after the passage of the stencil opening L. In consequence of the maintenanceof a sub-atmospheric pressure in tho conduit e, the stencil band is pressed freely against the cylindrical segment b and thereby closure of the apertures d is eii'eeted.

The cylindrical segment Z2 is preferably adjustable relatively to the projection lens p in such wise that exact synchronization of the pictorial and tonal reproductions can besecured.

To produce the stencil margin there may be used the punching device shown in Figs. 3 and 4, operating as follows The domains of the sources of sound F1 FB represented by rectangular fields on the projection surface A are rendered visible, for example by lights of different colour. In accordance herewith the film band and also the stencil band are slowly unwound at the same speed. The stencil band is led through the punching device disposed preferably alongside the projection apparatus, namely between the punches M and the grooved rolle r R serving as an anvil. Corresponding to the number of strips of the stencil band there are provided eight punches M which are brought into action by means of a like number of rock levers O, having slots O mounted o n a common rocking pivot P. The rock levers -O are provided at the lower end with notches O2 through which penetrates a pin Q. The pin Q is fitted at one end with two continuously reciprocatory rods S actuated by an eccentric T.

The notches O2 are so sha ed that the rock levers O are only engaged y the vibrating pin Q when the rock levers are moved downward for the length of the slots O. In order at will to bring the rock levers O individually into engagement with the pin Q each rock lever is connected by means of a link U with a lever V connected in turn by a rod W with a key lever X.

By depression of the keys X the relative rock levers O are moved downwards on the pin P, in opposition to a tension spring Y. lVh'en the key X is released the rock lever O returns automatically to its inoperative position. The keys X are preferably arranged relatively to one another in the same way as the fields of the projection surface representing the domains ofthe sources of sound. There is now to be observed on what field of the projection surface for example a player speaks. The key corresponding to this field is .then depressed for the duration of the speech soA that in the strip of' the stencil band corresponding to the field there is punched out a slot of length corresponding to the duration of the speech.

lVhat I claim as my invention and desire to secure by Letters Patent of the United States, is

The combination with a moving picture film and a sound producer controlling band moving synchronously with and forming part of the film and having a plurality of longitudinally extending zones, each zone controlling a different sound producer, of a plurality of different electrically actuated sound producer-s equal in number to the zones, and means for energizing the sound producers comprising a plurality of chambers, one for each sound producer, a tracker board having openings equal in number to the chambers, a tubular connection between each chamber and the corresponding opening in the tracker board, a valve seat in each chamber, an upwardly opening valvecoacting with the seat and having a stem extendingdownward through the chamber, a spring urging the valve upward, a vacuum producing means connected to each of said chambers at a point below the seats in said chambers, the lower end of the stem of each valve forming an electrical contact and being electrically connected to one terminal of the corres nding sound producer and a contact Ymem r disposed below and in normally spaced relation to the several contacts when the valves correlated to the several contacts are raised but electrically engaging said contacts when the valves are lowered.

.In testimony wlrlerof I have amxed my signature. A

. ROBERT KOLLER. 

